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Pressure signs-- opinions, pic's


Fred63

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A chronograph tells you how fast the bullet is going and maybe provides some statistical analysis comparing one shot to the others in a string. Nothing else.

Looking at primers is a very loose guide to pressure. There are lots of factors to consider, and you're just guessing. For people who have loaded a lot of ammo it may be an educated guess.

A good starting point is a manufacturer's published data. Generally you can stay in that range and be OK. Just be sure you are using the same or very similar components, overall length as the published data, and in a sound firearm.

Look at brass from quality factory ammo fired out of your gun. Factory ammo is generally within safe limits and tested with real ballistics equipment.

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I always chrono new loads, even middle range minor pf loads straight from published data so I know what I've got and to check for any unusual results or mistakes.

When loading 9 major there is no official data, only what we can pick up from others experience as in this forum.

I am shooting out of a Czechmate which is designed to operate with these loads.

I know I will have some evidence of pressure and would like to see some pic's of where you decided to stop.

Or do I keep increasing load until I get to the examples above, which we can all see are to high, and then drop 0.2grn and call it safe?

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No, that is not a good plan. With the right powder you should hardly see any pressure signs while shooting PF of 175. Just the beginning of the primer flattening, no more than that. Not even visible to a casual eye.

If you just stick to the two most popular powders: WAC and HS-6, and follow the standard recipes usually mentioned here, you should be safe and clean.

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Kneeingatlas that's what I was after, what you consider ok. Defanantly flattening and some cratering around firing pin. Are they soft primers? Loading now with WAC, starting 5.4-6.2 but with short OAL in Czechmate of 1.10 125 conical coated. Rainy weekend has not allowed testing yet so just fishing for as much info as possible.

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Kneeingatlas that's what I was after, what you consider ok. Defanantly flattening and some cratering around firing pin. Are they soft primers? Loading now with WAC, starting 5.4-6.2 but with short OAL in Czechmate of 1.10 125 conical coated. Rainy weekend has not allowed testing yet so just fishing for as much info as possible.

I load with SPP: CCI, WIN, and FED

1.10" is pretty short, the longer you load, the less pressure you'll get a the same PF. I've found my stock CZ chambers can load as long as 1.170" with round nosed plated bullets. WAC is about the fastest powder I would use for 9 major, I usually use SP2 (similar to 3N38); since you're in Australia, you should have access to SP2 right? HS6 is my second favorite.

Since I prefer 115s (I know the minimum bullet weight for IPSC Open major is 120 :( ) I've only ever chrono'd one WAC load with 124s: 7.3gr of WAC under a 124gr Xtreme plated RN @ 1.170" made 177pf through my 5.1" CZ barrel w/o holes. I've found these barrels to be significantly faster than my 2011 barrels: Schumann, KKM, and STI. Coated bullets should chrono faster and you should get more velocity at your shorter OAL, so I suspect your 6.2gr load might chrono ~160 PF.

Edited by kneelingatlas
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Can't find Vectan SP2, VihtaVuori 3n38, or Hodgdon hs6 listed with any suppliers within 100 miles and powder here is in store pickup only- show liscence.

The WAC I got is the first to arrive in two years.( to my club)

I've been looking for 125 RN for about 4 months but one of our larger local manufacturers ( Hawksbury River) has shut down to relocate and no one has stock of any type. If you sometimes have problems getting stuff at least you're not at the bottom of the supply chain

Now that I've gotten that out of my system

I will try with what I have just to get a workable load to be able to put some shots down range, but I suspect even if I can make pf I won't have enough gas off such a small load to be truly effective.

One of the few imported projectiles we get here are Berrys and when available have 124gn RN copper plated and 124gn HBRN-TP at $155/1000 but I have read mixed views as to weather these stand up to higher velocities,any experience with these in particular and are they worth the extra cost ?

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Fed spp with 9g of 3n38.

Yes, they are pierced and did 1100 fps over the chrono for these 2 and only 2 shot fired, demonsrating why chrono is data but doesnt necissarily tell you anything about pressure.

This same with cci spp are perfectly fine and doing 1430 fps with a 124.

post-28527-0-26605700-1467661901_thumb.j

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Wow 9x45, that piece of brass is amazing. Feed ramp bulge, extractor cut flow, primer completely melted into pocket, headstamp disappearing.

What is "extractor cut flow?

I think he meant to have a comma there, if you look at the case head and the extractor groove, you can clearly see dents in both from a very violent ejection.

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Wow 9x45, that piece of brass is amazing. Feed ramp bulge, extractor cut flow, primer completely melted into pocket, headstamp disappearing.

What is "extractor cut flow?

I think he meant to have a comma there, if you look at the case head and the extractor groove, you can clearly see dents in both from a very violent ejection.

So the case was molten hot and slammed back against the extractor so hard that it put those dents in the brass? That's pretty violent.

Thanks for the info...

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So the case was molten hot and slammed back against the extractor so hard that it put those dents in the brass? That's pretty violent.Thanks for the info...

Not molten but basically cold worked under very high pressure.

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